SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0894ffbb6982f656b67ddfec70401ca5555927a35ed517884b744b35b3851009' 
  AND token = 'v/FQ7QoQ0FKGJD/D+FOXEa2rONUY92H8pVe6gBFTH6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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