SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd927a4eb96a07a553c14367ea4a5f8e91a15e6b98a16fad612431592cdfa9d27' 
  AND token = '2dPrnI6nHXIKGXL8LywPTnOu04QUTArpy2rFD56Tzoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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