SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb5ccb0b6fe8b8f6ad9be633ff1593ea41e7320b118918ef7932aec3d32bfea8' 
  AND token = 'Nep9RHFrhqcxnwYpjArB+ngl2ElcvoDh6hAUVbreLWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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