SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10c1a1a9bf15c50d4b2e7174fb68ff89e75cf9c1115f0484331d5e7f28f16541' 
  AND token = 'oczCdsKzuEQIQ4vQCevS6OEpTW3+MHkTQDZIdnEh+Xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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