SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a0ee37663505956bdc4dd2133888c5ee5b118be868b2bd2bb4cb95313095bf8' 
  AND token = 'Ep22beJXxWfFb7G161H6grD+HRO/bxEbUYLoNGiiqbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}