SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a89afcc82e41fc5b48b187a63dd65a63862a814c172d1f4e2fc3131582c943c0' 
  AND token = 'k8Bor1HLEogAxzUlAlccrvBd9/qSQrbcReHq3t1Yftk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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