SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '402eeb583ed50b8681a913f587272bcb1d010446acfebf430c416922d19960be' 
  AND token = 'L89bnnJBJysKRLJBqcW3V3Zm7K5NNMbI8mjojDzV+qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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