SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fe24f69c412e678d18cb1cb5b9afffca1ce185872caf22ace3c149d448f150f' 
  AND token = 'W8nAy1ZvSKmFVpO75z59CjbUm963FmK3dPh2aCkEi40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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