SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '193cbdb408bb0e5903f13e2638b819b974e75769bf4995e7240bdf6306d3a97c' 
  AND token = 'cU3GCu03ZrShdlVQsoRkvODCVsmftaBz7OnUvD3BKQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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