SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e83904d2bb675ea30a151168be3c3c6b479c227dfa0eda02d4469c388f9049fd' 
  AND token = 'yM+43WqM/eeONVgD34jn9G3S15mGqzcDVk9w8QJY/cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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