SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dfdd896dd2697797cd8b023c679b5e404b9ad027f054568596533d200e7f86e' 
  AND token = 'TA/ceeUjGeSYl0bXtT+Fy/eEat7mBzGGJ+OruuBu0ZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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