SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b503997a84f45f8da4d0d49a61b020f1d8ed7b8459c97c7a186ca58c44f35c5b' 
  AND token = '8oJQmV4yjrjRU1P/8ONijHpJszDDxjS12GMtA1QU5CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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