SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '681c44744ac56c82a29619cfaf49e93bb1ff686fc6849296863731dc1219054e' 
  AND token = 'ByN4c/20Wblgmn7nImyjmeCdSj8NNDDXeJiYojnkR4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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