SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f34d375646fdb619e416d6e8a83be86a31228422714f16a5354235bec76f14c1' 
  AND token = 'ZCkiJvvcd0OigP3wBe5qBdOClWQi4jghnX6Y/jTvcFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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