SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d2a96ffa55de1b6456b8ef3d84554f15a813a33d03b50e3aaa5e25b29a978e9' 
  AND token = 'lk7YGj0kOOUCdclX+PMzc9kp7zwsJ+aGFcrGuC85t4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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