SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325e269adef8624d5533e6d8385f10fe4abb381790c45c135e05737c9961e16a' 
  AND token = 'LQvf3GrH5lD9xIZ2XgVZ2aMshfTZ5M7FaQLpkvzjuVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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