SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '241e42ef7a2e86ff665a4a677c64a594bff1bb18ae4e5d044f524731dc3fd1ff' 
  AND token = 'PSnxempa/dMQKEOkr+yb3jS52vPMPCIgNZ2sAxPLbpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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