SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c703358c0c3f3a14eed60f2fb51d5284cfe9d67d0ad44ed40ae16933048826d9' 
  AND token = 'uPEEDUCdGj+5kKfO10AVwKMNDe1SnvqU3HHJvoyzKqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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