SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '929ed390b50aeb84140b947ba2fb80887dcad124559ca87b0f3219795d2386af' 
  AND token = '5eZ+mms4lx664Jbcb+vMFyC6O5KKkAutdURpuMiNnZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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