SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '44b31b706dbcc544ce8713d91ea9f2e8c2315632e58da7a0cda0096db7ad1067' 
  AND token = 'fSpmUJRP6tt//23JsnQZ39vU24Szi+9jXefwfDU0//k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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