SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237a68b1c5cb4ca9c2950f442e95572cf4664548a6402dc2265dd54a6ab6f094' 
  AND token = 'wHv0w2VBpYjTK6QPVp1/y1cyMsbJiQh/uVOio+gv6ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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