SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1885330e33ec1ca7036a211b596607e134542250169ad7f999e7e8fd654c3435' 
  AND token = 'zubdkQOP9DClFjL506UjTvjaWGoHlqR+aeIebzni1lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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