SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d344f657b70555a195c4c8c797959f9564224e00ed399d7f456dc24d6d7195' 
  AND token = 'FzGsXbxkdj7Ly67aacRkIqu8sz+wtbW23uN4cwoPNm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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