SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b220581017c2209aa0295cf0d21455bc92adbc5071ea367e54b800aad977b7f' 
  AND token = 'bDSRKyIUJGt0l3vUxI+GHmUGyaGyXi8lMXzGksyIQzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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