SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4bb2ccdda352e0185be8edd52a525974ab1fc5b7be5dfd92d5d24bf9660ad53' 
  AND token = 'JrEtx8fy/0j4fj5Pk4PCYQrrJwgFfFa2FGB3Jk+Vup0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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