SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df65ef674f8c1f13f46fb2d854cdd69aa3cc26ff783bb79aad1222408c8fe72d' 
  AND token = 'XO83EyaJXU2uVUTM5HEDXDd7YWBaeB4GHZvvmWVsCUM=' 
  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"
    }
  }
}