SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd8ecce5e3a07a76c27d2a37558a8dde01e07915490e86f996d0feddf9b91bad6' 
  AND token = 'mc7XGgJvmHPA/jyDm9HarPzL2e4p4BKHm2dno2uEDYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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