SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b36ded8f7f870583166910266e72e51f9dfe007b1f80260f4e158a53d1f0c899' 
  AND token = 'CfRKY2I8g4ZGCNr05XQ1xoUkdZp40DFoHvoT/pL8eEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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