SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd367d0880f94d76052e488343d69194cb0b835c85d615bbd4dc6e83dfcee8b42' 
  AND token = 'EY194dait+QGMfodVQTblssCpfqfyG422lGveri+oB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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