SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d2ba9e61c1042cab67f19c62a63d7a107fc2f056d3041eaf4d2c6a4e83e6b9c' 
  AND token = 'MgfNOV+VUyIoDma0Uh/piZk0+5ugrHIPhLzxJwuBpaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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