SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5291394d59371fb4b49684c149d8740d232538739bc5314b3c073e28326b65b3' 
  AND token = 'Gh/5MWPmrnsfEnwUh/LFFrIPZ+ZXNRFoulQVsy/re2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}