SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6558300a2b695071bf7a2a4f9dfd1bc843663d38552c74046e7dddb9e6763d8b' 
  AND token = 'XSIYJtnB4mOTmHlDMSCqafogHCihNQc4/lEHATYsOKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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