SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '297cce0053c76d9dd2ffe34da91ad5e412aee75511db100e8b123fc077932495' 
  AND token = '04YRsTb9H23PBz1MOTRgrPnmUwSkDVa/vsMrzrgYP2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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