SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fd2eb7561c3342c300a7e8b5cdd712f7c32f03e08a713ace32afc6c5ca2ac93' 
  AND token = 'kMq0LdTPIRhrYSVg+nygTSMwL3Nma1gcnSgZPICgdTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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