SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a4e0bf2c93053f05b16bd066d9f0142ecaec8fca136761fdc4324982a3d26b' 
  AND token = '+4RlDsffYhkOzw2PMLyBF7sBkf2HkeU41waL6igCo2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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