SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bcdf4172548e6bd60406a4228df50717b85246bf48ef51e0ed58acd3f166db9' 
  AND token = 'Quyb6a3zQPnERNuf1HqQwS7q6yquVAFPaWiNtZ0uoWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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