SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7316a1e9f18c33d4b3f6e4ab00764fd1bd4f855363523e18921a426a18ea956' 
  AND token = 'JUJKfflu0xaFyVueK6ARHKoLERyEEZepkRcIAbSLutk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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