SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a549c801b3fc06bc5a60d8edc8566a1214d823b8cd15a89def06194fc85733d2' 
  AND token = '+1pOUQeNy18ekuscZjpf0RLerbH64RpqQAd+QhFh9rE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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