SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '189276b94311f926fe9b797e1d8ff5076111bcd84456f4fbd180a1ab9ffec438' 
  AND token = 'mrn+nTTr3fnMyBHAZhmEYYFgzSFWziF4GxHkv99QfUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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