SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b7d9bd64d6113188cbca94bd6e5f3c89d73c651479e477fd97f0e2c4c9da93e' 
  AND token = 'REkaXYKeqhHyNofHR74rwhBK9XaXfRioSh8dLYKbJ/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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