SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11811584744fd822bd499054e2cd516b0f06fc2535c9ed71406d663142dfcf04' 
  AND token = '34pHgi1oLy6KdLw5KqymdGdlMxCZoJJ6x99/Zd8oZpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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