SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7fd710259f282e315ec466e21dc20c7dbaa5061dd4798707054f8b3f39c450' 
  AND token = 'fLPvoaRWD4YfFLjtEGG0BbqTE7MyuEtEvLrbNuvUl5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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