SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92431d53c732b4436509eeaa8fde43dba3459c8c95c031a85bf6360ebc2ca6d' 
  AND token = 'NES47lynYe1ggwbxRnaQKMiT6a6SzjKl532Li9/ltao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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