SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0ce540bc4ce6c969c78cd8e673c37042ade5eb8263a3383f561632a7c3b050e' 
  AND token = 'jQwnGlRAkTIou5CcFukTE80937SReWnPWQ0zwKCA4hI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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