SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccfb565f0c6b5a578e822b599607eb7fe7294d2550746f3c3bb6806484b421e1' 
  AND token = 'SQsSEwKvCV9ivk2jvvHBwK/B3onLqgnKDLF77v/h3rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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