SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39336d272efe7974d1fca9b9c59aae0b12ff5de64187bdfe011124e32d5761a6' 
  AND token = 'Y8V8KJ5QFOEVQ1zyBNTY6mbD5hlDbKW8Gjt6V9qJesk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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