SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66be07348d279f5b8cf29659ed654f5306986c202d183b49ad524da20261679e' 
  AND token = '37vX/pGX83boVDfF3O+OihfbhqMrOh2ogx3f/h3HkKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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