SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb3e717164847606e067536df02be03017c9b0285f273f6642912a5215d79cc9' 
  AND token = 'VsfSMIlI8HXVwu5qQ0mFmEpSCqauV/IWSMADzfcPHd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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