SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd825c118e7b1a85768cb58b91cda80c9fa41ab2068988527807453f11d62fa7' 
  AND token = 'wZ8XcbUT3F1ReYO4JgiUGnHUORSrQcWQAUNMMIHfU0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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