SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9510ba5b350597fd1eedf9d6fe3baf690f9e4788714a96598c226febb87b013a' 
  AND token = 'Yo9rneIm8+toOqmOeXNr2fSChfCvovxxtHC4Q0Rk+s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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