SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e436aadafe34ca051d0a03447baed4c3f9b73e01be44419163572e5488109fd7' 
  AND token = 'LB6WDEPq87kkB6s+knUmfBTz1uf7OYgYS5pwINkx1J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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