SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '012ccc95af64188ed6921e361a94a796bcd82d1264517e898df918391d7ea97e' 
  AND token = 'dwuijAP4HMPgBEEhNP/Fgpn0CSbfVKm5ubHkK8roRYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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