SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da8ed40dd135be4f556ecbba07e11f811e6a489067805d0b9af04bec4646c950' 
  AND token = 'Z3SuF5XpJhNROgsr1exyCMzRfVtu+xTEdHt06kTB80w=' 
  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"
    }
  }
}