SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '767ac614375aa82ac064384cdd459a0c2ce2e5a2675631e6a74d83fd514fece7' 
  AND token = 'bhQYVkEf8UWu7KVCFgNno8In/DC/SXAHJ+O393OUU24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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