SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b3f8ed71010d36afe1df1cd7a544f51eb4839a583503ded25dbde586f04e6dd' 
  AND token = 'e4pD8QLhDJoubaLdyn7H0cAEZX3ez9+HNOYYzI5s/OY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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