SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df72b3861179712dd1e3735e4e9ae973c0dfe85a84b2206e5322d2a900af0e00' 
  AND token = 'pNH5jrH634BLWJDDwyLpchhOlRUZpURbmE1pt51ipu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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