SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf99b316a4d0abf8b9920ae4dd5e643f43288523f3443a099d5ee4bd14d0c06b' 
  AND token = 'DCybWqlhAsQFgehugskDC/2Vm5CkXryDADkFQUJykhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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