SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47d9180dde23cb7431dda1af91dc63f0fdaa898af6d842669f8591ad51203bb7' 
  AND token = 'cH+RowshKhqBQR2op/VsRDhY0nHlXj/A67doYlKjIaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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