SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1ec971323f7460d825b7f995a42c3b306dafac8990686866299841e0998386d' 
  AND token = 'GuEXzANDJYvxVgR2/IsmvUp09i3IP1Hd2E+IOjDUrAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}