SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10834d09f8cf488ecfbbdf2be139669fc021ea97f8a2f70745c9ef590254de3d' 
  AND token = 'qA2UBVrEsCCn/E73b4y90PpxgUrmEr2kVQrYjMD82jQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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