SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae1c8621afd18c4331ca8c455895a70e300183ff7d8966a83edc966ff509e786' 
  AND token = 'M5nxw84WDkxgCFbKbC0Ede76MHe9UjLlt2cpGYbRLTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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