SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cb0560b4026501332af8d741bcfb127b46e7db68a79829a13075726c1d81820' 
  AND token = 'MNg7tvnztrM7HJ+DHAkhJjRx9a0sBmfFnpfqzfMio94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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