SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc87a24270f5246ef87f8708eec1d54084bfee0220565871180385eaddd69926' 
  AND token = 'sbipX9pd52s6S7jpbtPjDLu4QGo2HD9BFzOm0zd1Dmk=' 
  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"
    }
  }
}