SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22f7cbb4f620fa8ec9b3285c1bfb8f6969ea6f1df08f85ae8a75ec69f6dfd788' 
  AND token = 'Pj4EkBfQyGvdYJiXgrBNwAAq4jdh3hkUQJ/aGE5Fzv4=' 
  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"
    }
  }
}