SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ed74b10837b2c087baede27ead607128848920406d088852d4c4c4cd690c4c4' 
  AND token = 'rcISGYPJuKFixz6IZB2NN7wLiQjvyH//prDoafjEJC4=' 
  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"
    }
  }
}