SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdae47a8b9a778fb7023d49be1d70a5b7fcaa2dfbb0b0567e91febf028f7c54e' 
  AND token = 'kEkI3Uwz1X5k/JQj+5nSXrjPay2P1Zltx8WIuo5X1Dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}