SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '066935f2724e7ce61478312242e2ab0f327fc595049f2458cefc863d5a0387f0' 
  AND token = 'f8UclSDp8I9ppN2F8BY2VyTfD/IT+/u7/hWhX5yjLOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}